Color photography



S J. M. ANDREAS 2,357,924

001.011 PHOTOGRAPHY Filed Feb. 20, 1941 Q DYE TRANSFER PRINTING YELLOWRECORD HAVING ABSORPTION MAX/MA IN THE BLUE AND DEEP RED REGIONS.

' ,firuerzw JEhTLM 6271.62 MMEJ his Q53 5.

Patented Sept. '12, 1944 colon rno'rocnsrnr John M. Andreas, Hollywood,Calif., assignor to Technicolor Motion Picture Corporation, Hollywood.Calif.. a corporation of Maine Application February 20, 1941, Serial No.879,771

9Claims. (01. 95-2) This invention relates to color photography and moreparticularly to photographic records composed of two or moresuperposedcolor aspect records in subtractive colors.

Some of the subtractive coloring matters commercially available-formaking color photographs are deficient because their spectral absorptionbands do not have the shape or location required by the reproductionprocess in which the are employed. Referring for example to three-colorphotography by the imbibition methodaccording to which color aspectrecords in subtractive dyes are transferred in superposition toa blankfilm from matrix films, many of the available cyan dyes .do not havesuiliciently strong absorption for (green absorbing) and cyan (redabsorbing) coiorlng matters. These coloring matters will in light at thefar red end of the visible spectrum.

As a consequence of this defect, blue colors may pear too violet in hueand shadows may be either insufficiently dense or too red.

It is the main object of the present invention to reduce this excessivetransmission (or reflectance,

in the ,case of reproductions intended to be viewed by reflected light)'of certain spectral ranges by photographic color records in'subtractivecoloring matters. In one aspect, the invention provides an improvedmethod for making color photographic records of this type using coloringmatters of particular characteristics; in another aspect, the inventionprovides improved records of this type by reproducing the blue aspect inyellow coloring matter which absorbs a certain portion of the red rangeof the visible spectrum; in still another aspect, the invention providescoloring matter of most instances be dyes, but it'is understood thatother coloring matters having similar optical characteristics may servethe same purpose; there-. fore, the term "dye will herein be'used todenote any such coloring matter. r

These three records (in; yellow, magneta and cyan dyes, respectively)maybe applied to s. single gelatin coating by transferring them in exactsuperposition to this coat "from three gelatin matrices. In this case,the threesubtractive dye records practically merge in-the gelatincoating e.

The subtractive color records may also be provided in the form of5090311 integral packs. In this case, three distinct emulsion layers maycontain records in yellow, magenta andcyan dyes,

respectively. At the present-time, such records are the subtractivecolors, yellow, magenta and cyan.

It is further feasible to combine various methods of subtractive colorphotography, for example by transferring a yellow dye record to anintegral this type which has satisfactory transfer properti'es if usedto reproduce color aspect records by the imbibition method.

These and other obiects and aspects of the in; vention will be. apparentfrom thefollowing de- Y scription of a practical embodiment illustratingits general characteristics. This description refers to a drawing inwhich:

Fig. 1 is aschematic'section through a three color photographic record:

' Pig. 2 is a digrammatic representation of dye absorptioncharacteristicsiaccording to the invention; and I 1 Fig. 3 is a flowdiagram explaining. a printing method according to the invention.

As indicated in Fig. 1, a photographic color record of the subtractivetype may consist ofa support 5, forexample a transparent'Celluloid film,

end a gelatin coating e carrying three records. 1 m and 0,01 the blue,green and red color aspects respectively, which records 'are printed orotherwise produced in yellow (blue absorbing) magenta pack emulsioncontaining the magenta and cyan records.

As mentioned above, the commercially available dyes, or the dyes forvarious reasons preferable for.

this purpose, are deficient because their absorption ranges do notextend over the entire spectral range which they should theoreticallysuppress. The cyan dyes are particularly deficient in this respect sincetheir absorption bands frequently do not cover the range of longer wavelengths toward the far red end of the visible spectrum,

which range will herein be referred to as deep II I this condition isindicated in Fig. 2. where Ail,

Amand Ac are the absorption curves of a set of yellow, magenta and cyandyes. and where An is the combined-or neutral absorption curve. -It'wil1be apparent from this diagram that it will not only be very diilicult toobtain neutral black 3 shadows of high density-since the usual yellowand magenta dye have essentially no absorption in the deep red and eventhe cyan is deficient in this region-but also that the hues of certaincolorsin the original will be reproducedincorrectly. A

' most objectionable result of this'condition is a tendency the shadowportions of the reproduction to appear brownish or dull red.

1 have found that this undesirable transmission Y oi the deep red bycertainparts of the picwe can be-greatlyreducedby providing theyello w"the ' records of the color reproductio which this new typeof yellowrecord is to be em-- record (for Fig. 1); with an additional absorptionband in the;deep" red'regi'on, the'a'dded absorp tion maximum beingprefcrablyinthe region:-.-

690-730 millimicrons, either .by using coloring.

matter-having this peculiar absorption characteristic or-by combiningcoloringmatters to furnish In the 'latterinstancei nicmeavesconndenmy.

same indl t y 2 The particular eilectwhich is most desirableiand-zthemost suitable combination of dyes to produce it will depend upon thecharacteris ics of the other process: with Ployed. It should be .notedin this connection that the dye which has an absorption band inthe deepred may also have an absorption band in the blue region. If it does havean absorption bandin the blue region, it will have the generalappearance of a green or olive colon: Such a dye cannot be added toeitherthemagenta or cyan recordabecauseit would degradethe'rendition ofblue colors, but it .can-be-used toadvantage in theyellow'record.

With reference to Fig. 3', the essential stepsof an actually usedreproduction technic'. incorporating the. invention will now bedescribed by way of example; In thisflgure, My, Mm and Me representthree-gelatin matrices made inthe.

records com the two dyes as amixture', they couldlbe sepa-.ratelyiapplied in consecutive printing operations.

, It will also be understood that theuse or this ,deepred absorbing dyein the picture area might be only foneo'f several functions which'thsdye W P rms: F r-example; in motion pic-f ture rsoundtfilm theqdeepred" absorbing dyemay i-be employed ifoa miukinkdrimm-linesror soundtrack or bothfin additionto factor; in: lilfoducingi improvedflcolor;reproduction i'nthe picture mat-3%.?

packs azi'oriexamplq -the wanes-ems com- .peiisatingifunction 1s s1mtteawill-t be; developed to produc'e'..ai. dye image havingthe .desiredab-"ysorptlon, for exampl by initially incorporating infthe blue-aspectlayer or-in its developing solution two color formers which, asthedevelopment of the silver record proceeds, produce a record in two,dyes; one absorbing mainly the blue and the-other'the deep red spectralregion. 1

' It should be understood that the present disclosure is for the purposeof illustration only'and that this invention includes-all modificationsand equivalents which fall within the scope of the appended claims.

I claim:

1. In the art or making colored photographic d of superposed records ofthe blue, green and red color aspects'in the sub- F tractive ,coloringmatters yellow, magenta and cyan, the cyan coloring matter nothavingsuiiici'ently strong absorption forlight atthe far redconventional'manner by exposing three matrix films through theirsupports'to threecolorseparation records, hardening the gelatincoextensive with the exposed silver halide and. removing the unexposed"portions. The gelatin of these relief matrices is loaded with theappropriate dyes, the cy printing-matrix with conventional cyan dye'having itsmaximum absorption of about 650 millimicron's, the magentaprinting matrix with dye having its maximum absorptionatabout 535millimicrons, and the yellow printing matrix with dye from an aqueoussolution having the'following composition; I

- gallant Papef Yellow km?) (0.1."

This dye mixture has the-desired characteristic 364) n -grams/liter..3.0 'Naphthol GreenJB Conc. .(DuP) (10-11 5) am/liter 1.0 Glacial aceticacid.-...... per cent of providing. absorption maxima in the blue and"-deep red'spectralregions, and the dyes transfer in such a waythatrelatively more green'is-pres ent in the shadows than in the highlightsof the; yellow record.

These three matrices. are then consecutively.

in exact -register, brought into contact with the,

elatin layer of the positive ,blanlr film P. pro I ducing. therein-a.three' color; record 'in' subtr'active dyes, with-thetransmissionofthe-deep red region reduced to a degree essentially eliminatingtheabove-mentloned disadvantages and yet not unfavorably disturbing thegeneral color rendition.

It will be understood that, instead of applying end of. .the spectrumand .thus causing a preponderance of red in the finished record; themethod comprising printing said records magenta and cyan in registeredsuperposition by dye transfar from matrices, and similarlyp'rinting therec 0rd yellowima mixture of 'two dyeco'mponents; I 7 one componentabsorbingthe blue spectral irange and thej-other component the deepfredrange and-the ratioiof said two components presentin .all densities ofthe record being approximately j constant, in amountsuiilcientsubstantially to reduce said-preponderance of red in the finishedrecord: 4

making colored photographic records comprised'of superposed records ofthe blue, green and, red color aspects in; the 'sub- 2.- In the art oftractive coloring matters yellow, magenta and cyan, the cyan coloringmatter not having sufflciently strong absorption for light at the farred end or the spectrum and thus causing a preponderance of red intheilnished record, the method comprising printing said records magentsand cyan in registered"superposition by dye transfer from matricesgandsimilarlyprlnting the recordyellow in a mixture of two dye componentapnecomponentwabsorbing the blue spectral-range and the other component thedeep range,.relatiyely-more of the deep redabsorbing'component -beingpresentin the ah lights than in: the shadows; of the blue? aspectrecord, in amount sufllcient substantially toi -educe said"preponderance of red in. the finished recordrf blue, green d .0010!aspectsiinthe'subtractive coloring matters yellow, magenta and, cyan.the-cyan coloringmatter not having sumciently strong absorption forlightat the far red ltl-will' b'exz ll ther understood-that the inyention=.'can,- bezffanalogo uslyappli d other. W q flW :cd e Producflmtp mIn 1 the mstanceabf oolor deuelopediintegral ,mono.

' 3; In theart ofmaking colored .photographic records comprised of supeposed, records of the e 2,857,92; I Y 3' absorption maximum in said deepred spectral end of the spectrum and thus causing a preponderance-of redin the finished record, the method being present in the highlights thanin the shadows of the'biue aspect record, in' amount su'fllcientsubstantially to reduce said preponderance ot red in the finishedrecord.

4. A colored photographic record, comprising a support carrying inregistered superposition two records absorbing the green and redspectral ranges respectively and transmitting the deep red spectralrange, and a third record having an absorption maximum in the bluespectral range and another absorption maximum in said deep red spectralrange, whereby the third recrd has maximum absorptionat opposite ends orthe spectrum and theabsorptionor the first two records is confinedsubstantially to'intermediate ranges.

5.; A colored photographic record comprising a supp rt carrying inregistered superposition two records absorbing the green and redspectral ranges respectively and transmitting the'deep red spectralrange, and a third record comprising two dye components, one componenthaving an absorption maximum in the blue spectral range and the otherdye component having an range, whereby the third record hasmaximumabsorption at opposite ends of the spectrum and the absorption of thefirst two records is confined 6 substantiallytointermediate ranges. v

6. A colored photographic record accordingtov claim further,characterized in that the ratio of the first component to thesecondcomponent is greater in the high lights than in the shadows.

l0 7. A colored photographic record according to claim 4 furthercharacterized in that said third record comprises naphthol green dye. I

8. A colored photographic record according to claim '4 furthercharacterized in that said third record comprises brilliant yellow dyeand naphthol green dye;

'9. In the art 01 making colored photographic records comprised ofsuperposed records of the blue, green and red color aspects in thesubtractive coloring matters yellow, magenta and cyan,

the cyan coloring matter not having sufliciently strong absorption forlight'at the far red end of the spectrum and thus causing apreponderance ofred in the finished record, the method comg tprisingprinting said records magenta and cyan "in registered superposition bydye transfer from matrices, and similarly printing the record yellow inatmixture of two dye components, one component absorbing the bluespectral range and the other component the deep red range in amountsufiicient substantially to reducesaid preponderance 01 red in thefinished record.

qorm M. ANDREAS.

